Joseph banks



J. BANKS. ROTARY PUMP,

No. 39,540. Patented Aug. 18, 1863.

UNITED STATES PATENT *FFicE.

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IMPROVEMENT m- ROTARY PUMPS.

Specification forming partof Letters Patent No. 39 540, dated August 18, 1863.

'I'ooZZ whom it may concern.-

Be it known that I, Josnrn BANKS, of the city, connty and State of New York, have invented a new and useful Improvement in Ro tary Pumps; and I do hereby declare that the following is a full, clear, and exact description This invention relates to an improvement ini that class of rotary pumps which I have described in Letters Patent granted to me September 23, 1862, and in which a piston-wheel with four sliding pistons revolves in an eccem trio cylinder.

The object of my present improvement is to produce a tight joint between the edges and ends of the sliding pistons and the inner surface and heads of the cylinder by simple and easily adjustable means.

The cylinder A is made of cast-iron or any other suitable material, with two openings, 0:. 1,0116 to connectwith the suction-pipe and the other with the ascension-pipe. The inner surface of this cylinder is bored out to a perfectly true circle, and the heads B, which are secared to the cylinder by means of screws or in any other desirable manner, are provided with central holes which form the bearings-for the shaft 0, to which the piston-wheel Dis rigidly attached.

. Eis the inner case, which covers a little over one half of the inner surface of the cylinder, as clearly shown in Fig.1 of the drawings.- This case is so arranged thatits thickest-part touches the surface oi'the pistonwhcel, and consequently an open crescentshaped space is left between the surface of the piston-wheel and the inner surface o'f'the cylinder opposite to the inner case and. equah to the thickness of said case. The pistonwheel is provided with four (more or less,

sliding pistons, F, and instead of forcing these pistons out by means of springs-interposed between them, as described in my former-patent, I now connect the-opposite pistons by stems a, so that the same are compelled to move simultaneously, one moving in when the other moves out, and vice versa. Each piston is provided with two spring-valves, G G, which are fitted into slots or grooves in the edges of said pistons. overlap each other, either in the center or towardone end of the piston, in order to clear the holes in the cylinder, and said valves are forced out by springs I) 0' co in a radial and in a lateral direction. By the action of the springs b b the valves are forced out toward thc inucr surface of the cylinder, and by the springs c c a tight joint is produced between the ends of the valves and the heads of the cylinder. By the action of the springs L h" the valves are contin un-lly held in contact with the inner circumference of the cylinder, not withstanding the variations in its diameter, and by connecting the pistons they have a solid bearing throughout the whole stroke, so that they are not liable to bind even when exposed to a high pressure. Fnrthermorc,by fitting the spring-valve into slots or grooves in the edges of-the pistons they are securely guided and not liable to be forced off when subjected to a severe strain. If desired, the pistons can be made in two'parts, ,a plate, d, being secured on one side by means of grooves e,.as shown in Fig.4 of the drawings. By this arrangement the introduction of the spring-valves is facilitated, and I am enabled -to make that portion of the piston which is exposed to the: most severe strain of steel, so as to make it last longer, and to be able to replace the some w-henworn out. The pistons may also be provided with channels f on their inner sides, through which the liquid in the cylinder is allowed to act on the inner edges of the spring-valve. In this case the liquid itself will keep the valves up tight to the cylinder with more or less force, ac-

cording to its own pressure. By these means The two valves of each piston.

the strain on the springs 12 b a 0 will be re- 2. The spring s b b underthe'valves G G, dueed and they will be less liable to wear out when the same are used in combination with than without such liquid packing. pistons F, connected by stems a, in the manner What I claim as new, and desire to secure and for the purpose substantially as specified. by Letters Patent, is-- JOSEPH BANKS.

1. Arranging the valves G G in slots or re- Witnesses: cesses in the edges of the pistons F, as and i R013. H. LOUDER, for the purpose shown and described. GEO. W. REED. 

